Jet pump adaptor for ventilation system

ABSTRACT

In accordance with the present invention, there is provided an adaptor or attachment which is suitable for integration into the patient circuit of a ventilation system, such as a non-invasive open ventilation system, is configured for attachment to any standard ventilation mask, and is outfitted with a jet pump which creates pressure and flow by facilitating the entrainment of ambient air. The adaptor comprises a base element and a nozzle element which are operatively coupled to each other. The base element further defines a throat and at least one entrainment port facilitating a path of fluid communication between the throat and ambient air. The nozzle element includes a jet nozzle, and a connector which is adapted to facilitate the fluid coupling of the nozzle element to a bi-lumen tube of the patient circuit. The connector includes both a delivery port and a sensing port. The jet nozzle and the delivery port collectively define a delivery line or lumen which fluidly communicates with the throat of the base element, and is placeable into fluid communication with the delivery lumen of the bi-lumen tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/020,032, filed Sep. 6, 2013 and entitled “JET PUMP ADAPTOR FORVENTILATION SYSTEM,” the entire disclosure of which is whollyincorporated by reference herein.

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to systems and methods for controllingdelivery of a pressurized flow of breathable gas to a patient and, moreparticularly, to an adaptor or attachment which is suitable forintegration into the patient circuit of a ventilation system, such as anon-invasive open ventilation system, is configured for attachment toany standard ventilation mask, and is outfitted with a jet pump tofacilitate the entrainment of ambient air.

2. Description of the Related Art

As is known in the medical arts, mechanical ventilators comprise medicaldevices that either perform or supplement breathing for patients. Thevast majority of contemporary ventilators use positive pressure todeliver gas to the patient's lungs via a patient circuit between theventilator and the patient. The patient circuit typically consists ofone or two large bore tubes (e.g., from 22 mm ID for adults to 8 mm IDfor neonatal) that interface to the ventilator on one end, and a patientmask on the other end. Most often, the patient mask is not provided aspart of the ventilation system, and a wide variety of patient masks canbe used with any ventilator.

Current ventilators are designed to support either “vented” or “leak”circuits, or “non-vented” or “non-leak” circuits. In vented circuits,the mask or patient interface is provided with an intentional leak,usually in the form of a plurality of vent openings. Ventilators usingthis configuration are most typically used for less acute clinicalrequirements, such as the treatment of obstructive sleep apnea orrespiratory insufficiency. In non-vented circuits, the patient interfaceis usually not provided with vent openings. Non-vented circuits can havesingle limb or dual limb patient circuits, and an exhalation valve.Ventilators using non-vented patient circuits are most typically usedfor critical care applications.

Vented patient circuits are used only to carry gas flow from theventilator to the patient and patient mask, and require a patient maskwith vent openings. When utilizing vented circuits, the patient inspiresfresh gas from the patient circuit, and expires CO2-enriched gas, whichis typically purged from the system through the vent openings in themask. When utilizing non-vented dual limb circuits, the patient inspiresfresh gas from one limb (the “inspiratory limb”) of the patient circuitand expires CO2-enriched gas from the second limb (the “expiratorylimb”) of the patient circuit. Both limbs of the dual limb patientcircuit are connected together in a “Y” proximal to the patient to allowa single connection to the patient mask. When utilizing non-ventedsingle limb circuits, an expiratory valve is placed along the circuit,usually proximal to the patient. During the inhalation phase, theexhalation valve is closed to the ambient and the patient inspires freshgas from the single limb of the patient circuit. During the exhalationphase, the patient expires CO2-enriched gas from the exhalation valvethat is open to ambient.

In the patient circuits described above, the ventilator pressurizes thegas to be delivered to the patient inside the ventilator to the intendedpatient pressure, and then delivers that pressure to the patient throughthe patient circuit. Very small pressure drops develop through thepatient circuit, typically around 1 cmH2O, due to gas flow though thesmall amount of resistance created by the tubing. Some ventilatorscompensate for this small pressure drop either by mathematicalalgorithms, or by sensing the tubing pressure more proximal to thepatient.

In the prior art, ventilation systems are know which integrate either aventuri or a jet pump. Generally speaking, a venturi functions to speedup a fluid in a tube using a restrictor to create negative pressure. Incontrast, a jet pump uses a high speed jet in ambient air to facilitatethe entrainment of ambient air. Along these lines, the prior artincludes ventilation systems which incorporate entrainment masks and areused for the purpose of delivering air in combination with anothertherapeutic gas (e.g., oxygen) to a patient. For example, high flowoxygen delivery systems exist that include an air entrainment maskwhich, in addition to being designed to fit over the patient's nose andmouth and to connect to oxygen supply tubing, comprises a jet orificeand air entrainment ports. Oxygen under pressure is forced through asmall jet orifice entering the mask. The velocity increase causes ashearing effect distal to the jet orifice, which in turn causes room airto be entrained into the mask via the ports formed therein. These oxygentherapy entrainment systems are used to, among other things, deliverproper mixtures of air and oxygen.

However, the prior art is generally lacking in providing non-invasiveopen ventilation systems wherein a jet pump, as opposed to a venturi, isintegrated into the tubing of a patient circuit, rather than into thepatient interface or mask of the patient circuit. The present invention,as will be described in more detail below, addresses this deficiency inthe prior art.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided an adaptoror attachment which is suitable for integration into the patient circuitof a ventilation system, such as a non-invasive open ventilation system,is configured for attachment to any standard ventilation mask, and isoutfitted with a jet pump which creates pressure and flow byfacilitating the entrainment of ambient air. The preferred patientinterface used in conjunction with the adaptor of the present inventionis a non-vented (or non-leak) nasal mask or full face mask (FFM).However, the adaptor may also be used in conjunction to a traditionalvented nasal mask or full face mask, such as those used for continuouspositive airway pressure (CPAP), bi-level PAP or bi-level therapy.

In accordance with a first embodiment of the present invention, theadaptor comprises a base element and a nozzle element which areoperatively coupled to each other. More particularly, the nozzle elementmay be rotatably connected to the base element as allows for therotation of the nozzle element relative to the base element. The baseelement defines a standard 22 mm ISO taper connector which allows forthe releasable attachment of the adaptor to any standard ventilationmask. The base element further defines a throat and at least oneentrainment port facilitating a path of fluid communication between thethroat and ambient air.

The nozzle element includes a jet nozzle, and a connector which isadapted to facilitate the fluid coupling of the nozzle element to abi-lumen tube of the patient circuit, such bi-lumen tube defining both agas delivery lumen and a sensing lumen which is fluidly isolated fromthe gas delivery lumen. The connector includes both a delivery port anda sensing port. The jet nozzle and the delivery port collectively definea gas delivery line or lumen which fluidly communicates with the throatof the base element, and is placeable into fluid communication with thedelivery lumen of the bi-lumen tube. In addition, the nozzle and baseelements, when attached to other, collectively define a pressure sensingline or lumen which is fluidly isolated from both the delivery lumen andthe throat, and is placeable into fluid communication with the sensinglumen of the bi-lumen tube. In this regard, a portion of the sensinglumen is defined by the base element (including the sensing portthereof), with another portion of the sensing lumen being defined by thenozzle element. These separate portions of the sensing lumen are broughtin fluid communication with each other when the nozzle element isconnected to the base element. The jet nozzle, in combination with thethroat and the entrainment port, creates a jet pump within the adaptor.It is contemplated that the nozzle element can be molded with differentjet nozzle sizes in order to change the performances of the jet pump(e.g., more or less pressure or flow) and can further be color coded sothat the user can easily understand the jet pump performance providedthereby.

In the patient circuit outfitted with the adaptor, the jet pump in thepatient circuit is able to generate a maximum pressure of about 30 cmH2O (and preferably about 20 cm H2O), and a peak flow of about 100 l/min(and preferably 60 l/min). Pressure and flow are generated in a mannerwherein the breathable gas (O2, air, or other mixtures of breathablegas) is delivered to the jet nozzle of the jet pump and ambient air isentrained through the entrainment port. The flow of pressurized air isdelivered to the patient through the standard ISO taper connection withthe non-vented mask. The pressure sensing line of the adaptor is used tosense the pressure in the mask or to trigger a breath whenbreath-by-breath ventilation is provided by the ventilation system. Inthe first embodiment, the gas exhaled by the patient may be exhaustedthrough the entrainment port. It is further contemplated that an HMEand/or antibacterial filter can be connected between the jet pump andthe connector of the mask.

In accordance with a second embodiment of the present invention, the jetpump of the adaptor may be equipped with an anti-asphyxia valve (AAV) inorder to reduce the back pressure during exhalation. More particularly,an exhalation valve or AAV may be used to decrease expiratory pressurein the case when the throat of the jet pump is too small or in case offailure of the ventilator or gas source. The valve may incorporate aconical diaphragm valve that is stretched to seal against one or moreexhalation ports of the adaptor (which are separate from the entrainmentport) when there is positive pressure and flow in the jet pump, andopens in a manner unblocking the exhalation ports when the jet pump isnot activated (i.e. during exhalation). The same function can beachieved thorough the use of a flapper valve as an alternative to theaforementioned diaphragm.

In accordance with a third embodiment of the present invention, the jetpump of the adaptor may be equipped with a exhalation/positive endexpiratory pressure (PEEP) valve (or a connection for a third party PEEPvalve). More particularly, the jet pump may incorporate a pilotedexhalation valve. The valve can be piloted between on/off states orcould be piloted in a proportional fashion to achieve positive endexpiratory pressure (PEEP) control by using the pressure in the deliveryline that feeds the jet nozzle via a pilot line. In this way, the valveopens and closes in sync with the breathing pattern of the patient.During inhalation, when the jet flow is delivered to the jet pump, thevalve is closed by the high pressure in the nozzle delivery lumen.During exhalation there is either no flow delivered by the jet nozzle(and hence no pressure in the delivery lumen) and the valve opens, or asmall flow and pressure can be maintained in the delivery lumen so thatthe jet pump can create back pressure in the throat against exhalationand the valve can be servoed with positive pressure to vary theresistance. This latter system results in a controllable PEEP value andrequires a careful sizing and matching of the jet pump performances atlow flow and the PEEP valve characteristic. This is made easier using aclosed loop control over the pressure sensed by the sensing lumen of thepatient circuit. The valve can also be used as a PEEP valve by using aspring to maintain PEEP and the pilot line to close during inhalation.In this embodiment the PEEP value can be adjusted by changing thepre-load of the spring (e.g., by rotating a portion of the housing).Optionally, for a better PEEP control, a non-return valve (e.g. anumbrella valve) can be used to close the throat of the jet pump duringexhalation.

In accordance with a fourth embodiment of the present invention, the jetpump of the adaptor may employ a fixed PEEP valve in the shape of, forexample, a flapper valve at the end of the throat. The valve is normallyclose (i.e., rests against the throat of the jet pump) and opens duringinhalation when positive pressure and flow are established by the jetflow coming from the jet nozzle. During exhalation the jet flow issuspended and the valve returns in its close state. On the surface ofthe valve a plurality of holes ensure that the exhaled gas can beevacuated to the ambient by building a back pressure sufficient tomaintain PEEP in the patient's airways. A range of different valves canbe realized so that different PEEP values can be achieved. Color codingcan be used to identify the PEEP value. The perforated flapper valve isjust one of several modalities which may be used to achieve the samefunction. Along these lines, the perforations on the flapper could bereplaced by grooves on the sealing surface of either the valve or theseat of the throat. The umbrella valve can be used in a similar fashion,with or without orifices/holes within the same.

The present invention is best understood by reference to the followingdetailed description when read in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These, as well as other features of the present invention, will becomemore apparent upon reference to the drawings wherein:

FIG. 1 is a front perspective view of an exemplary prior art masksuitable for use in conjunction with any jet pump adaptor constructed inaccordance with the present invention;

FIG. 2 is a front perspective view a jet pump adaptor constructed inaccordance with a first embodiment of present invention;

FIG. 3 is a bottom view of the jet pump adaptor shown in FIG. 2 ;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3 ;

FIG. 5 is a bottom view of the base element of the jet pump adaptorshown in FIGS. 2-4 ;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5 ;

FIG. 7 is a rear perspective view of the nozzle element of the jet pumpadaptor shown in FIGS. 2-4 ;

FIG. 8 is a front perspective view of the nozzle element of the jet pumpadaptor shown in FIGS. 2-4 ;

FIG. 9 is a graphical representation of typical characteristic curvescorresponding to the functionality of the jet pump adaptor of the firstembodiment, the curves being parameterized with jet flow;

FIG. 10 is a cross-sectional view a jet pump adaptor constructed inaccordance with a second embodiment of present invention;

FIG. 11 is a cross-sectional view a jet pump adaptor constructed inaccordance with a third embodiment of present invention; and

FIG. 12 is a cross-sectional view a jet pump adaptor constructed inaccordance with a fourth embodiment of present invention.

Common reference numerals are used throughout the drawings and detaileddescription to indicate like elements.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings for which the showings are for purposes ofillustrating preferred embodiments of the present invention only, andnot for purposes of limiting the same, FIG. 1 depicts an exemplary priorart patient interface or mask 10 suitable for use with the jet pumpadaptor 12 of the present invention, as will be described in more detailbelow. As indicated above, the preferred patient interface used inconjunction with the adaptor 12 of the present invention is a non-vented(or non-leak) nasal mask or full face mask, the mask 10 being anon-vented full-face mask. In this regard, the mask 10 comprises a bodyportion 14 which is sized and configured to cover the nose and mouth ofa patient. In addition to the body portion 14, the mask 10 includes atubular connector portion 16 which is fluidly coupled to the bodyportion 14. As also indicated above, though the adaptor 12 is preferablyused in conjunction with the non-vented mask 10, the same may also beused in conjunction with a traditional vented nasal mask or full facemask.

The adaptor 12 as constructed in accordance with a first embodiment ofthe present invention is shown with particularity in FIGS. 2-8 . Theadaptor 12 comprises of base element 18 (as shown in FIGS. 5 and 6 ) anda nozzle element 20 (as shown in FIGS. 7 and 8 ) which are operativelycoupled to each other. More particularly, the nozzle element 20 may berigidly, rotatably, or threadably connected to the base element 18 in amanner which will be described in more detail below, the rotatable andthreadable connections allowing for the selective rotation of the nozzleelement 20 relative to the base element 18.

As is best seen in FIGS. 2-6 , the base element 18 includes a connector22 which is preferably a standard 22 mm ISO taper connector. In thisregard, due to its preferred structural attributes, the connector 22allows for the releasable attachment of the base element 18, and hencethe adaptor 12, to any standard ventilation mask, including theexemplary mask 10 shown in FIG. 1 . In this regard, by way of example,the connector 22 is adapted to receive and releasably accommodate theconnector portion 16 of the mask 10. In addition to the connector 22,the base element 18 defines a throat 24. More particularly, the throat24 is defined by a tubular wall 19 which has a generally circularcross-sectional configuration and protrudes into the interior of theconnector 22, as seen in FIGS. 4 and 6 . The configuration shown inFIGS. 4 and 6 , wherein the tubular wall 19 protrudes into the interiorof the connector 22, is exemplary only, and is used to reduce theoverall length of the adaptor 12. Adaptors for ISO tapers smaller than22 mm may have a different architecture and, more particularly, may belonger than the adaptor 12. The wall 21 defines a distal end or rim 21.That end of the throat 24 circumvented by the rim 21 fluidlycommunicates with the interior of the connector 22. The base element 18also defines at least one air entrainment port 26 which fluidlycommunicates with the throat 24. More particularly, as is also apparentfrom FIG. 6 , the entrainment port 26 facilitates the fluidcommunication of the throat 24 with ambient air. Still further, the baseelement 18 defines an elongate pressure sensing line or lumen 25 whichextends in side-by-side relation to, but is fluidly isolated from, thethroat 24. Like the throat 24, one end of the pressure sensing lumen 25terminates at the rim 21 of the wall 19 and fluidly communicates withthe interior of the connector 22. In this regard, a portion of thepressure sensing lumen 25 extends through the wall 19. The opposite endof the pressure sensing lumen 25 terminates at a recess 27 which isformed within that end of the base element 18 opposite the end definedby the connector 22. The use of the recess 27 will be described in moredetail below. In the base element 18, an aperture or opening 23 extendsbetween the throat 24 and the bottom, innermost surface of the recess27.

As best seen in FIGS. 2-4 and 7-8 , the nozzle element 20 includes a jetnozzle 28 and a connector 30 which is adapted to facilitate the fluidcoupling of the nozzle element 20, and hence the adaptor 12, to abi-lumen tube of a patient circuit including the adaptor 12 and mask 10.Though not shown, such bi-lumen tube defines both a gas delivery lumenand a sensing lumen which is fluidly isolated from the gas deliverylumen. The jet nozzle 28 has a generally frusto-conical externalconfiguration or shape, and protrudes from a circularly configuredmandrel portion 29 of the nozzle element 20. The connector 30 of thenozzle element 20 includes both a tubular gas delivery port 32 and atubular pressure sensing port 34 which, as best seen in FIG. 7 , residewithin a common recess 31. The recess 31 is formed within that end ofthe nozzle element 20 opposite that defined by the distal end the jetnozzle 28 protruding from the mandrel portion 29.

In the adaptor 12, the recess 27 formed within the base element 18 has aconfiguration which is complementary to that of the mandrel portion 29of the nozzle element 20. In accordance with the present invention,three (3) different attachment modes may be achieved between the baseand nozzle elements 18, 20. In a first attachment mode, the base andnozzle elements 18, 20 are rigidly secured to each other. Moreparticularly, the circularly configured mandrel portion 29 is advancedinto the complementary, circularly configured recess 27 and securedtherein by way of, for example, glue, a weld, or a press fit. In asecond attachment mode, the base and nozzle elements 18, 20 arerotatably connected to each other. In this regard, the rotatableconnection of the nozzle element 20 to the base element 18 isfacilitated by the slidable receipt of the circularly configured mandrelportion 29 into the complementary, circularly configured recess 27. In athird attachment mode, the base and nozzle elements 18, 20 arethreadably connected to each other. Though not shown, the threadableconnection of the nozzle element 20 to the base element 18 may befacilitated by the engagement of male threads formed on the circularlyconfigured mandrel portion 29 to complementary female threads formedwithin the circularly configured recess 27. As is seen in FIG. 4 , inany of the aforementioned attachment modes, the advancement of themandrel portion 29 into the recess 27 is limited by the abutment of ashoulder 40 defined by the nozzle element 20 and circumventing themandrel portion 29 thereof against an end surface 42 defined by the baseelement 18 and circumventing the recess 27 form therein. Both prior toand when such abutment occurs during the advancement of the mandrelportion 29 into the recess 27, an annular gap or channel 44 of aprescribed width is defined between the outer, distal surface of themandrel portion 29 and the bottom, innermost surface defined by therecess 27.

The advancement of the mandrel portion 29 into the recess 27 facilitatesthe concurrent advancement of the jet nozzle 28 through the opening 23.In this regard, as further seen in FIG. 4 , in the opening 23 ispreferably formed to have a diameter which is only slightly less thanthat of the base of the jet nozzle 28 which extends to the outer, distalsurface of the mandrel portion 29. This is done so that when the jetnozzle 28 is advanced through the opening 23, a gas-tight (albeitslidable or rotatable) coupling is formed by the interference betweenthe jet nozzle 28 and the circumferential surface of the base element 18defining the opening 23. A similar gas-tight coupling or fit is alsopreferably achieved between the circumferential outer surface defined bythe mandrel portion 29 and the circumferential inner surface defined bythe recess 27 when the mandrel portion 29 is advanced into the recess27. When the shoulder 40 is abutted against the end surface 42, the jetnozzle 28, by virtue of having been advanced through the complementaryopening 23, protrudes into the throat 24 of the base element 18 and isvisible within the entrainment port 26. The aforementioned channel 44circumvents the base of the jet nozzle 28. It is contemplated that theopening 23 may be outfitted with a seal, the configuration of whichprovides for the aforementioned gas-tight coupling of the jet nozzle 28to the base element 18, yet allows for the rotation of the jet nozzle 28within the opening 23 in the event either the rotatable or threadableattachment modes between the base and nozzle elements 18, 20 areimplemented in the adaptor 12.

In the nozzle element 20, the jet nozzle 28 and the gas delivery port 32of the connector 30 collectively define a gas delivery line or lumen 36which fluidly communicates with the throat 24 of base element 18 whenthe nozzle element 20 is coupled to the base element 18. As is also mosteasily seen in FIG. 4 , when the nozzle element 20 is connected to thebase element 18, the gas delivery lumen 36 and the throat 24 extendalong a common axis A, with the axis of the pressure sensing lumen 25 ofthe base element 18 extending in spaced, generally parallel relation tosuch axis A. The gas delivery lumen 36 and the throat 24 collectivelydefine a gas delivery conduit of the adaptor 12. The gas delivery lumen36, and hence the gas delivery conduit, is placeable into fluidcommunication with the gas delivery lumen of the bi-lumen tube in amanner which will be described in more detail below.

As best seen in FIGS. 4, 7 and 8 , the pressure sensing port 34 of theconnector 30 partially defines a pressure sensing line or lumen 38 ofthe nozzle element 20. That end of the pressure sensing lumen 38opposite the end defined by the pressure sensing port 34 terminates atthe outer, distal surface of the mandrel portion 29, as seen in FIG. 8 .When the nozzle element 20 is connected to the base element 18, thepressure sensing lumen 36 also extends in spaced, generally parallelrelation to the axis A, with the pressure sensing lumens 25, 38 andintervening channel 44 collectively defining a pressure sensing conduitof the adaptor 12. Since, as indicated above, the pressure sensing lumen25 of the base element 18 is formed to fluidly communicate with therecess 27 thereof, such pressure sensing lumen 25 thus fluidlycommunicates with the channel 44 when the nozzle element 20 is connectedto the base element 18. Similarly, since the channel 44 is annular andcircumvents the jet nozzle 28 as indicated above, the pressure sensinglumen 38 is maintained in a constant state of fluid communication withthe channel 44, irrespective of the orientation of the nozzle element 20relative to the base element 18 if it is rotatably or threadablyconnected thereto. As such, the integrity of the pressure sensingconduit of the adaptor 12 collectively defined by the pressure sensinglumens 25, 38 and intervening channel 44 is not compromised by anyrotation of the nozzle element 20 relative to the base element 18 duringuse of the adaptor 12, assuming that the nozzle element 20 is notrigidly attached to the base element 18. Further, irrespective ofwhether the nozzle element 20 is rigidly, rotatably or threadablyconnected to the base element 18, the inclusion of the channel 44 in thepressure sensing conduit allows the pressure sensing lumen 25 to bedisposed further radially outward relative to the axis A in comparisonto the pressure sensing lumen 38 while being maintained in a constantstate of fluid communication therewith by the channel 44. The pressuresensing lumen 38, and hence the pressure sensing conduit, is placeableinto fluid communication with the pressure sensing lumen of the bi-lumentube in a manner which will be also described in more detail below.

It is contemplated that the adaptor 12 as described above will beintegrated into a patient circuit wherein a main delivery tube, and moreparticularly the aforementioned preferred bi-lumen tube, is used tofacilitate the fluid communication between a flow generator orventilator and the adaptor 12 (and hence the mask 10 coupled to theadaptor). More particularly, the bi-lumen tube is advanced into therecess 31 such that the gas delivery port 32 of the connector 30 iscoaxially aligned with an advanced into the gas delivery lumen of thebi-lumen tube. Similarly, the pressure sensing port 34 of the connector30 is coaxially aligned with and advanced into the pressure sensinglumen of the bi-lumen tube. As will be recognized, is contemplated thatthe cross-sectional configuration of the gas delivery lumen of thebi-lumen tube will be complementary to the configuration of the gasdelivery port 32 of the connector 30 such that the gas delivery port 32is frictionally maintainable within the gas delivery lumen of thebi-lumen tube upon being advanced therein. Similarly, thecross-sectional configuration of the pressure sensing lumen of thebi-lumen tube will preferably be complementary to the configuration ofthe pressure sensing port 34 of the connector 30 such that the pressuresensing port 34 is frictionally maintainable within the pressure sensinglumen of the bi-lumen tube upon be advanced therein. Bonding agents suchas glue, or other techniques, can also be used to retain the bi-lumentube within the nozzle element 20. As is further seen in FIG. 7 , thedistal end portion of the pressure sensing port 34 preferably has atapered configuration to assist in the advancement thereof into thepressure sensing lumen of the bi-lumen tube. As will be recognized bythose of ordinary skill in the art, the advancement of the bi-lumen tubeinto the recess 31 is limited by the abutment of the corresponding endof such bi-lumen tube against the bottom, innermost surface defined bythe recess 31.

In the adaptor 12, the gas delivery conduit (as defined by the gasdelivery lumen 36 through the jet nozzle 28 and the throat 24) incombination with the entrainment port 26 creates a jet pump whenpressurized gas is introduced into the gas delivery conduit by thebi-lumen tube coupled to the adaptor 12. In a patient circuit outfittedwith the adaptor 12, is contemplated that such jet pump will be able togenerate a maximum pressure of pressure of about 30 cm H2O (andpreferably about 20 cm H2O), and a peak flow of about 100 l/min (andpreferably 60 l/min). Pressure and flow are generated in a mannerwherein a breathable gas (O2, air, or other mixtures of breathable gas)is delivered to the jet nozzle 28 of the jet pump and ambient air isentrained through the entrainment port 26. The flow of the pressurizedgas mixture (including the entrained air) is delivered to the patientthrough the connector 22 and the mask 10 coupled thereto. The gasexhaled by the patient may be exhausted through the entrainment port 26.Though not shown in FIGS. 2-8 , is contemplated that a heat and moistureexchange device (HME) and/or an anti-bacterial filter can be connectedbetween the jet pump and the connector portion 16 of the mask 10.

It is contemplated that in the adaptor 12, the nozzle element 20 can bemolded with anyone of a multiplicity of different sizes of the jetnozzle 28 in order to selectively change the performance of the jet pump(e.g., more or less pressure or flow). Further, it is contemplated thatthe nozzle element 20 may be color-coded so that the user can easilyunderstand the jet pump performance provided thereby. Along these lines,it is further contemplated that the adaptor 12 may be configured suchthat the nozzle element 20 thereof may be switched out to one having analternative configuration so as to selectively modify the performance ofthe adaptor 12.

In the adaptor 12, the performance of the jet pump is predominatelydriven by the geometric factors of the size of the jet nozzle 28 (nozzlesize), the size of the throat 24 (throat size), and the distance fromthe distal end of the jet nozzle 28 to the end of the throat 24 ascircumvented by the base of the wall 19 disposed furthest from the rim21 (nozzle-to-throat distance). In the adaptor 12, it is contemplatedthat the throat size will be fixed, and that if the base and nozzleelements 18, 20 are rigidly or rotatably secured to each other, thenozzle-to-throat distance will be fixed as well. On the other hand, ifthe base and nozzle elements 18, 20 are threadably secured to eachother, the nozzle-to-throat distance may be varied to selectively modifythe performance characteristics of the jet pump, as will be described inmore detail below. However, even the case of a rigid or rotatableconnection between the base and nozzle elements 18, 20, the nozzle sizemay be varied as indicated above, so as to selectively adjust or modifythe performance of the jet pump. Along these lines, it is furthercontemplated that if the base and nozzle elements 18, 20 are rigidly orrotatably secured to each other, an even wider range of variation in thejet pump range can be achieved by pairing every nozzle element 12 with abase element 18 in which the throat size and the nozzle-to-throatdistance have been designed to optimize performance. However, a similarrange of increased performance can also be achieved by only varyingnozzle size and having variable jet flow. This is possible when usingthe adaptor 12 in a non-invasive open ventilation system instead ofconnecting it to a fixed flow source. Along these lines, the outfittingof the adaptor 12 with the pressure sensing conduit allows for theimplementation of the adaptor 12 in, for example, a close pressure loopcontrol with an non-invasive open ventilation system. The range ofvariability of performance of the jet pump with the jet flow is depictedgraphically in FIG. 9 . The graph is a typical characteristic curve ofthe jet pump where the curves are parameterized with the jet flow, anddemonstrate that increasing the jet flow increases the jet pumpperformances. The embodiment of the adaptor 12 shown and describedabove, as well as those embodiments described below, can also be usedwith a flow regulator instead of within a non-invasive open ventilationsystem. This practically means that the user will select a fixed flowvalue for the jet nozzle 28, with the performances of the jet pump beingrepresented by a single line corresponding to the set jet flow in thegraph of FIG. 9 .

Though the structural and functional features of the adaptor 12 asassembled using the attachment mode wherein the base and nozzle elements18, 20 are rigidly secured to each other could be implemented in aunitary construction rather than a two-piece construction, the use ofthe two-piece construction provides certain manufacturing advantages andeconomies. More particularly, by having a two-piece construction, ageneric base element 18 may be provided, with any one of a multiplicityof nozzle elements 20 each having differently configured jet nozzles 28being rigidly secured to the base element 18 in the aforementionedmanner. As indicated above, the nozzle elements 20 may be color-coded,thus providing a visual indication of the performance features of theadaptor 12 even subsequent to the rigid attachment of the base andnozzle element 18, 20 to each other.

As indicated above, the base and nozzle elements 18, 20 may bethreadably secured to each other to allow for selective variations oradjustments in the nozzle-to-throat distance for purposes of modifyingthe performance characteristics of the jet pump. In this regard, in thethreadable connection attachment mode described above, the rotation ofthe nozzle element 20 in a clockwise direction relative to the baseelement 18 would effectively shorten the nozzle-to-throat distance.Conversely, the rotation of the nozzle element 20 in a counter-clockwisedirection relative to the base element 18 would effectively lengthen thenozzle-to-throat distance.

Referring now to FIG. 10 , there is shown an adaptor 112 constructed inaccordance with a second embodiment of the present invention. Theadaptor 112 comprises the adaptor 12 shown in FIGS. 2-8 and describedabove, but enhanced in a manner wherein the jet pump is equipped with anexhalation or anti-asphyxia valve (AAV) 146 in order to reduce the backpressure during exhalation. More particularly, the valve 146 may be usedto decrease expiratory pressure in the case when the throat 24 of thejet pump is too small or in case of failure of the ventilator or gassource.

In the adaptor 112, the valve 146 comprises a generally cylindrical,tubular housing 148 which includes at least one, and preferably a pairof exhalation ports 150 formed therein. The housing 148 is attached tothe connector 22 of the base element 18, and is releasably engageable tothe connector portion 16 of the mask 10. The valve 146 further comprisesa resilient, conical diaphragm 152 which is disposed within the interiorof the housing 148, and is selectively movable between open and closedpositions relative thereto. As seen in FIG. 10 , the end of thediaphragm 152 of greatest diameter is defined by a radially extendingflange portion thereof which is captured between the housing 148 and thedistal end or rim of the connector 22 of the base element 18.

When there is positive pressure and flow in the jet pump of the adaptor112, the diaphragm 152 is stretched to its closed position to sealagainst (and thus close or block) the exhalation ports 150 (which areseparate from the entrainment port 26). Conversely, when the jet pump isnot activated (i.e. during exhalation), the diaphragm 152 moves to theopen position shown in FIG. 10 , thus unblocking the exhalation ports150. The same function can be achieved thorough the use of a flappervalve as an alternative to the aforementioned diaphragm 152.

Referring now to FIG. 11 , there is shown an adaptor 212 constructed inaccordance with a third embodiment of the present invention. The adaptor212 comprises the adaptor 12 shown in FIGS. 2-8 and described above, butenhanced in a manner wherein the jet pump is equipped with aexhalation/positive end expiratory pressure (PEEP) valve. Moreparticularly, the jet pump of the adaptor 212 comprises a pilotedexhalation valve 246.

The valve 246 comprises a housing 248 which is attached to the connector20 of the base element 18. As seen in FIG. 11 , the housing 248 definesa hollow interior chamber 249 which fluidly communicates with theinterior of the connector 20. The housing 248 has a generally circularcross-sectional configuration, with the interior chamber 249 thereof(when viewed from the perspective shown in FIG. 11 ) defining a lowersection which protrudes from the connector 20 and is of a firstdiameter, and a distal upper section which is of a second diameterexceeding the first diameter. The lower and upper sections of theinterior chamber 249 are separated from each other by a continuous,annular shoulder 250 defined by the housing 248.

Disposed within the upper section of the interior chamber 249 andextending diametrically there across is a resilient diaphragm 252 of thevalve 246. When viewed from the perspective shown in FIG. 11 , thediaphragm 252 effectively segregates the upper section of the interiorchamber 249 into an upper region and a lower region, the lower regionextending to the shoulder 250. The housing 248 includes at least oneexhaust port 251 which is formed therein and fluidly communicates withthe lower region of the upper section of the interior chamber 249. Theupper region of the upper section of the interior chamber 249 ispreferably placed into fluid communication with the gas delivery lumen36 or the gas delivery lumen of the bi-lumen tube of the exemplarypatient circuit including the adaptor 212 via a pressure line 254extending therebetween.

In the valve 246, the diaphragm 252 is selectively movable between anopen position (shown in FIG. 11 ) and a closed position. When thediaphragm 252 is in its open position, an open fluid flow path betweenthe interior of the connector 20 and ambient air is defined by, insuccession, the lower section of the interior chamber 249, the lowerregion of the upper section of the interior chamber 249, and the exhaustport 251 formed in the housing 248. When the diaphragm 252 is actuatedto its closed position, the same is effectively seated and sealedagainst the shoulder 250 in a manner effectively blocking the exhaustport 251 from fluid communication with the lower section of the interiorchamber 249, and hence the interior of the connector 20. The valve 246may further optionally include a spring 256 which is disposed within theupper region of the upper section of the interior chamber 249, andextends between the approximate center of the diaphragm 252 and acorresponding section of the interior surface of the housing 248.

Due to its inclusion of the diaphragm 252, the valve 246 of the adaptor212 can be piloted between on/off states or may be piloted in aproportional fashion to achieve positive end expiratory pressure (PEEP)control by using the pressure in the gas delivery lumen 36 or the gasdelivery lumen of the aforementioned bi-lumen tube of the patientcircuit that feeds the jet nozzle 28 via the gas delivery lumen 36. Asindicated above, this pressure is delivered is to the valve 246, and inparticular the diaphragm 252 thereof, by the pressure line 254. In thisway, the valve 246 opens and closes in sync with the breathing patternof the patient. During inhalation, when the jet flow is delivered to thejet pump of the adaptor 212, the diaphragm 252 of valve 246 is closed bythe high pressure in the gas delivery lumen 36 or the gas delivery lumenof the aforementioned bi-lumen tube. During exhalation there is eitherno flow delivered by the jet nozzle 28 (and hence no pressure in the gasdelivery lumen 36) and the diaphragm 252 of the valve 246 opens, or asmall flow and pressure can be maintained in the gas delivery lumen 36so that the jet pump can create back pressure in the throat 24 againstexhalation and the valve 246 can be servoed with positive pressure tovary the resistance. This latter system results in a controllable PEEPvalue and requires a careful sizing and matching of the jet pumpperformances at low flow and the PEEP characteristic of the valve 246.This is made easier using a closed loop control over the pressure sensedby the pressure sensing lumen of the patient circuit comprising thepressure sensing conduit of the adaptor 212 and the pressure sensinglumen of the bi-lumen tube. The valve 246 can also be used as a PEEPvalve by using the spring 256 (if included) to maintain PEEP and thepilot line 254 to facilitate the closure of the diaphragm 252 duringinhalation. In this embodiment the PEEP value can be adjusted bychanging the pre-load of the spring 254 (e.g., by rotating a portion ofthe housing 248). Optionally, for a better PEEP control, a non-returnvalve 258 (e.g. an umbrella valve) can be used to close the throat 24 ofthe jet pump throat during exhalation. As shown in FIG. 11 , the valve258 preferably resides within the interior of the connector 22, and isselectively engageable to the rim 21 of the wall 19 in a manner whichwill effectively close the corresponding end of the throat 24.

Referring now to FIG. 12 , there is shown an adaptor 312 constructed inaccordance with a fourth embodiment of the present invention. Theadaptor 312 also comprises the adaptor 12 shown in FIGS. 2-8 anddescribed above, but enhanced in a manner wherein the jet pump isequipped with a fixed PEEP valve in the shape of, for example, a flappervalve 346 cooperatively engaged to the wall 19 at the rim 21 thereof,and thus disposed at the end of the throat 24. The flapper valve 346 isnormally closed (i.e., rests against the throat 24 of the jet pump, andin particular the rim 21 of the wall 19) and opens during inhalation (asshown in FIG. 12 ) when positive pressure and flow are established bythe jet flow coming from the gas delivery lumen 36 via the jet nozzle28. The flapper valve 346 also opens in the case of a failure of thesource of breathable gas as a result of a negative pressure beingestablished on the patient side of the flapper valve 346 due to therespiratory effort of the patient. During exhalation, the jet flow issuspended and the flapper valve 346 returns in its closed state. Theflapper valve 346 preferably includes a plurality of holes orperforations 348 therein to ensure that the exhaled gas can be evacuatedto the ambient via the entrainment port 26 by building a back pressuresufficient to maintain PEEP in the patient's airways. Any one of a rangeof flapper valves 346 have differing configurations can be selectivelyused so that different PEEP values can be achieved in the adaptor 312.Along these lines, color coding can be used to identify the PEEP valuecorresponding to the particular flapper valve 346 integrated into theadaptor 312. The perforated flapper valve 346 is just one of severalmodalities which may be used to achieve the same function. Along theselines, the perforations 348 in the flapper valve 346 could be replacedby grooves on the sealing surface thereof, or grooves formed within theseat of the throat 24, i.e., the rim 21 which circumvents the distal endof the throat 24. The same functions may also be achieved by using, forexample, and umbrella valve or any other non-return valve having adesign which lends itself to the implementation of the working principleexemplified by the adaptor 312.

As indicated above, in each of the above-described embodiments, the jetnozzle 28, in combination with the throat 24, the entrainment port 26and the gas delivery lumen 36, creates a jet pump within the adaptor 12,112, 212, 312. As explained above, the present invention contemplatesthe use of various techniques to selectively vary the performanceattributes of the jet pump as may be need to provide a prescribedtherapeutic treatment. However, the jet pump, in any embodiment, isoperative to provide a prescribed level of pressure and flow to the mask10 with the use of a small diameter main gas delivery tube (e.g., theaforementioned bi-lumen tube) within the patient circuit.

This disclosure provides exemplary embodiments of the present invention.The scope of the present invention is not limited by these exemplaryembodiments. Numerous variations, whether explicitly provided for by thespecification or implied by the specification, such as variations instructure, dimension, type of material and manufacturing process may beimplemented by one of skill in the art in view of this disclosure.

What is claimed is:
 1. An adaptor for fluidly coupling a flow generatorto a ventilation mask in a respiratory assistance system, the adaptorcomprising: a connector which is fluidly connectible to the ventilationmask and defines an interior; a tubular wall which protrudes into theinterior of the connector and at least partially defines a throat, thetubular wall having a distal end which fluidly communicates with theinterior of the connector and a proximal end which is opposite thedistal end; at least one entrainment port in open fluid communicationwith ambient air, the at least one entrainment port being at leastpartially defined by an aperture in the tubular wall between the distalend and the proximal end; a jet nozzle in fluid communication with a gasdelivery lumen of a main gas delivery tube that is connectable to theflow generator, the jet nozzle having a distal tip that is positionedwithin the throat at a distance from the distal end of the tubular wallto fluidly communicate gas into the throat with at least a portion ofthe at least one entrainment port between the distal tip of the jetnozzle and the distal end of the tubular wall, such that when gas isflowed through the gas delivery lumen, out the jet nozzle, and into thethroat, ambient air is entrained through the at least one entrainmentport; and a pressure sensing lumen in fluid communication with a sensinglumen of the main gas delivery tube via an annular gap, the pressuresensing lumen extending through the adaptor in side-by-side relation to,and not within, the throat.
 2. The adaptor of claim 1 wherein theconnector is sized and configured to allow for releasable attachment ofthe adaptor to the ventilation mask.
 3. The adaptor of claim 2 whereinthe connector is a standard 22 mm ISO taper connector which allows forthe releasable attachment of the adaptor to the ventilation mask.
 4. Theadaptor of claim 1 wherein the annular gap circumvents a portion of thejet nozzle; with the pressure sensing lumen, the sensing lumen of themain gas delivery tube, and the annular gap being fluidly isolated fromgas flowed through the gas delivery lumen and into the throat throughout360° rotation of the jet nozzle relative to the throat.
 5. The adaptorof claim 1 further comprising a second connector which allows forreleasable attachment of the adaptor to the main gas delivery tube. 6.The adaptor of claim 5 wherein the second connector comprises: a gasdelivery port in fluid communication with the jet nozzle; and a pressuresensing port which at least partially defines the pressure sensinglumen; the gas delivery and pressure sensing ports at least partiallyresiding within a common recess of the adaptor and extending inside-by-side relation to each other.
 7. The adaptor of claim 1, whereinthe distal tip of the jet nozzle is positioned within the throat at aposition along an axis of the throat.
 8. The adaptor of claim 1, whereinthe position of the nozzle within the throat is selectively variablebetween at least two configurations so as to permit the distance fromthe distal tip of the jet nozzle to the distal end of the tubular wallto be varied by transitioning the position of the nozzle within thethroat to one of the at least two configurations.
 9. The adaptor ofclaim 1, wherein the jet nozzle and the tubular wall are provided inseparate pieces that are removably connectable to each other.
 10. Theadaptor of claim 1, wherein the jet nozzle and the tubular wall areprovided in a single piece as a unitary construction.
 11. An adaptor forfluidly coupling a flow generator to a ventilation mask in a respiratoryassistance system, the adaptor comprising: a connector which is fluidlyconnectible to the ventilation mask and defines an interior; a tubularwall which protrudes into the interior of the connector and at leastpartially defines a throat, the tubular wall having a distal end whichfluidly communicates with the interior of the connector and a proximalend which is opposite the distal end; at least one entrainment port inopen fluid communication with ambient air, the at least one entrainmentport being at least partially defined by an aperture in the tubular wallbetween the distal end and the proximal end; a jet nozzle in fluidcommunication with a gas delivery lumen of a main gas delivery tube thatis connectable to the flow generator, the jet nozzle having a distal tipthat is positioned within the throat at a distance from the distal endof the tubular wall to fluidly communicate gas into the throat with atleast a portion of the at least one entrainment port between the distaltip of the jet nozzle and the distal end of the tubular wall, such thatwhen gas is flowed through the gas delivery lumen, out the jet nozzle,and into the throat, ambient air is entrained through the at least oneentrainment port; and an exhalation valve, the exhalation valvecomprising: a housing which is attached to the connector and fluidlycommunicates with the throat, the housing including at least oneexhalation port formed therein; and a resilient, conical diaphragm whichis disposed within the housing and cooperatively engaged thereto, thediaphragm being selectively movable between open and closed positionsrelative to the housing; and wherein positive pressure and flow in thethroat facilitates the stretching of the diaphragm from its openposition wherein the exhalation port is unblocked thereby to its closedposition wherein it seals against and thus blocks the exhalation port.12. The adaptor of claim 11, wherein the jet nozzle and the tubular wallare provided in separate pieces that are removably connectable to eachother.
 13. The adaptor of claim 11, wherein the jet nozzle and thetubular wall are provided in a single piece as a unitary construction.14. An adaptor for fluidly coupling a flow generator to a ventilationmask in a respiratory assistance system, the adaptor comprising: aconnector which is fluidly connectible to the ventilation mask anddefines an interior; a tubular wall which protrudes into the interior ofthe connector and at least partially defines a throat, the tubular wallhaving a distal end which fluidly communicates with the interior of theconnector and a proximal end which is opposite the distal end; at leastone entrainment port in open fluid communication with ambient air, theat least one entrainment port being at least partially defined by anaperture in the tubular wall between the distal end and the proximalend; a jet nozzle in fluid communication with a gas delivery lumen of amain gas delivery tube that is connectable to the flow generator, thejet nozzle having a distal tip that is positioned within the throat at adistance from the distal end of the tubular wall to fluidly communicategas into the throat with at least a portion of the at least oneentrainment port between the distal tip of the jet nozzle and the distalend of the tubular wall, such that when gas is flowed through the gasdelivery lumen, out the jet nozzle, and into the throat, ambient air isentrained through the at least one entrainment port; and a pilotedexhalation valve, the piloted exhalation valve comprising: a housingwhich is attached to the connector and defines an interior chamber whichfluidly communicates with the throat, the housing including at least oneexhaust port formed therein; and a resilient diaphragm which is disposedwithin the interior chamber and effectively segregates the same into anupper region and a lower region which fluidly communicates with the atleast one exhaust port, the diaphragm being selectively movable betweenan open position wherein the at least one exhaust port is placed intofluid communication with the throat, and a closed position wherein theat least one exhaust port is blocked from fluid communication with thethroat.
 15. The adaptor of claim 14, wherein the jet nozzle and thetubular wall are provided in separate pieces that are removablyconnectable to each other.
 16. The adaptor of claim 14, wherein the jetnozzle and the tubular wall are provided in a single piece as a unitaryconstruction.
 17. The adaptor of claim 14 further comprising a pressureline which facilitates fluid communication between the upper region ofthe interior chamber and the gas delivery lumen.
 18. The adaptor ofclaim 14 further comprising a biasing spring disposed within the upperregion of the interior chamber and extending between the diaphragm andthe housing.
 19. The adaptor of claim 14 further comprising a resilientflapper valve which is cooperatively engaged to the tubular wall andselectively movable relative thereto between a closed position whereinthe flapper valve at least partially obstructs flow into the throat andan open position wherein flow from the throat is substantially unimpededby the flapper valve.
 20. The adaptor of claim 19 wherein the flappervalve includes a plurality of perforations formed therein.